The maxchannelCount property of the AudioDestinationNode interface is an unsigned long defining the maximum amount of channels that the physical device can handle.

The AudioNode.channelCount property can be set between 0 and this value (both included). If maxChannelCount is 0, like in OfflineAudioContext, the channel count cannot be changed.

An unsigned long.

The following would set up a simple audio graph, featuring an AudioDestinationNode with maxChannelCount of 2:

const audioCtx = new AudioContext();
const source = audioCtx.createMediaElementSource(myMediaElement);
source.connect(gainNode);
audioCtx.destination.maxChannelCount = 2;
gainNode.connect(audioCtx.destination);

To see a more complete implementation, check out one of our MDN Web Audio examples, such as Voice-change-o-matic or Violent Theremin.

• Using the Web Audio API